The water-gas shift (WGS) reaction can be used in conjunction with steam reforming of methane or other hydrocarbons to produce high purity hydrogen. Current methods based on this reaction proceed in two stages: a high-temperature shift on a first catalyst followed by a low temperature shift on a second catalyst. In these methods, fuel gas streams derived from the reformation or gasification of fuels often contain sulfur compounds that are not tolerated by commercial high-temperature water-gas shift catalysts.
The reverse water gas shift (RWGS) reaction is of particular interest for space exploration. For example, this reaction can allow conversion of gases on Mars into water, which, upon electrolysis, gives oxygen for use as fuel.
There is a need for sulfur-tolerant high-temperature catalysts for both the WGS reaction and the RWGS reaction.